Officials say the information is proprietary and releasing it could endanger public safety.

Nebraska recently responded to a records request from The Associated Press.Federal officials say they don't believe the information railroads provide to states must be withheld to protect the public.

This spring railroads were ordered to notify states about trains carrying at least 1 million gallons of crude oil.

Railroads are under pressure to improve safety after several fiery derailments involving crude oil, including one in a small Canadian city in eastern Quebec where 47 people died last July when 60 cars derailed and exploded.